Mixing and spraying rigs have been used for years by builders to apply textured and/or acoustical materials to walls and ceiling of buildings. The equipment used for such processes has made great strides over the years as evidenced by U.S. Pats. Nos. 2,596,074 HAWES, 2,815,767 KURNS and 3,889,850 WHITT. In spite of the progress made, numerous problems remain with the prior equipment which makes operation of the equipment and application of the materials less efficient than is desirable.
Mixing and spraying equipment is notorious for having numerous breakdowns. Such breakdowns are typically due to the fact that the equipment comprises a large number of mechanical parts such as pulleys, chains, belts, sprockets, gears and clutches. Breakdowns, resulting in down-time at the job site, are a well known frustration of laborers in the industry. Some prior art devices such as that disclosed by Whitt in his U.S. Pat. No. 3,889,850, went a long way to reduce the number of pulleys, chains, belts, gears and clutches. However, a certain number of gears, pulleys, belts and chains still remain and still breakdown.
Another frustration of laborers utilizing prior art mixing and spraying equipment is the frustration of down-time occurring during the materials mixing process. This is due to the prior art equipment constraints which require that the machine be either used for mixing or used for spraying. Thus, during the mixing process, the user cannot be applying materials to the building, and vice versa.
At least a few prior art systems, including the Whitt apparatus, have sought to use hydraulics, hydraulic pumps and motors, to lessen the number of mechanical parts required on the mixing and spraying apparatus. In spite of their good efforts, problems still remain in the design of the various pre-existing hydraulic systems which render the prior equipment incapable of performing multiple functions simultaneously, and, which also have made it necessary to maintain at least a vestage of mechanical parts such as pulleys, gears, belts and chains as driving components of the apparatus.
It has also been observed that prior art systems encounter difficulty with clogged spraying hoses due to the absence of filtering systems or the existence of in-line filtering systems (in the material spray hose) which require cleaning out or other maintenance. Furthermore, remote control of the hydraulic motor effecting material flow to the nozzle is typically accomplished in the prior art by the cumbersome use of dual flow control devices (i.e. by-pass valve and solenoid valve combination of U.S. Pat. No. 3,889,850) which control the amount of hydraulic fluid flowing through the hydraulic motor. Such prior art techniques provide unsatisfactory control of the material flow.